LIMACINEA. 173 



LIGULATE. (Liffula, a slip, a shoe-latchet.) Thin, slender, like 

 a slip, or neck of any thing, as the anterior muscular impression 

 of Lucina, fig. 104. 



LIGUMIA. Sw. A sub-genus of Unio, thus described : — "Very 

 long and pod -shaped ; bosses depressed; cardinal teeth mode- 

 rate. S. recta. Lam. vi. I. p. 74." Sw. p. 378. 



LIGUUS. Montf. A genus containing species of Achatina, 

 Auct. which have rounded apertures and lengthened spires, dif- 

 fering from his Polyphemi, which have lengthened apertures. 

 A. virginea, Auct. fig. 286, is the type of this genus. 



LIMA. Brug. {Lima, a file.) Fam. Pectinides, Lam. Subos- 

 tracea. Bl. — Descr. Equivalve, inequilateral, compressed, oblique- 

 auriculated, oval, radiately ribbed or striated, imbricated, covered 

 with a light brown epidermis ; hinge with a triangular disc between 

 the umbones, divided in the centre by a triangular ligamentary pit 

 without teeth ; muscular impression one, sublateral, sub-orbi- 

 cular. — 05s. The shells thus described are marine, two or three 

 species being found on our coasts, and fossil species occurring in 

 Lias, inferior Oolite, Caleaire-grossier, &c. They differ from 

 Pecten in having a wide hiatus for the passage of a byssus, by 

 which they are occasionally attached, and also in the triangular 

 disc, which separates the umbones. The animal makes use of 

 the valves of his shell as natatory organs, working them like fins 

 or paddles, and by this means proceeding at a rapid rate through 

 the waters. L. Squamosa, fig. 174. 



LIMACINA. Cuv. (Limax, a snail.) Fam. Pteropoda, Lam. — 

 Descr. Papyraceous, fragile, planorbicular, sub-carinated, ob- 

 liquely convolute ; spiral side rather prominent, the other side 

 umbilicated ; aperture large, entire, not modified, peristome 

 sharp. — Obs. This is Spiratella, Bl. The shell figured as 

 Limacina in Sowerby's Genera, under " pteropoda," is an Atlanta. 

 Our representation of Spiratella Limacinea, fig. 224. is copied 

 from Blainville. 



LIMACINEA. Lam. A family of the order Gasteropoda, Lam. 

 including the following genera: — 



